1. Field of the Invention
The subject invention generally relates to a seat assembly for a vehicle, and more specifically to a seat assembly including a rotatable seat bottom and a seat back that can rotate to absorb energy.
2. Description of the Related Art
School buses include a seat assembly for transporting occupants and, more specifically, school buses incorporate several seat assemblies into the school bus in rows. The seat assembly includes a seat bottom extending generally horizontally and a seat back coupled to the seat bottom and extending generally vertically relative to the seat bottom. Typically, the occupants are free to move about the school bus without being restrained in the seat assembly. In other words, the occupants are not buckled into seat belts to restrain movement of the occupants.
Seat assemblies are currently regulated by safety requirements, such as the National Highway Transportation Safety Administration's (NHTSA) Federal Motor Vehicle Safety Standards (FMVSS). For example, FMVSS 222, require that the seat back collapses, i.e., rotates from an upright position forward or rearward, to absorb energy from an occupant during a crash of the vehicle to reduce impact between the occupant and the seat back. As another example, Further, FMVSS 217 requires that seat assemblies adjacent an auxiliary exit door are required to have seat cushions that automatically flip up when not in use so that a clear aisle to the auxiliary exit door exists.
When a bus not equipped with seat belts is abruptly stopped, such as during a collision, unbelted occupants typically uncontrollably move under their own momentum relative to the seat assembly. For this reason, FMVSS 222 requires that during a front-end collision, the seat back typically folds forward when the occupant uncontrollably moves forward and hits the seat back such that the seat assembly absorbs energy from the uncontrollably moving occupant. Such an arrangement is referred to in industry as compartmentalized seating. Also, the seat back typically folds rearward when the occupant seated in the seat assembly collides with the seat back during a rear-end collision or during rebound after a front-end collision.
Recently a longstanding debate as to whether school buses should be equipped with seat belts has intensified and, as a result, more and more school buses are now being equipped with seat belt assemblies. Public pressure is building to require all school buses be equipped with seat belt assemblies. A strong consensus has already developed requiring the seat belt assemblies include a lap/shoulder belt combination similar to designs now installed in most modern automobiles.
In a vehicle, a seat belt assembly is mounted to the seat back and the seat back remains stationary relative to the vehicle in order for the seat belt to properly lock and restrain the occupant. However, in such a configuration, the benefits of the compartmentalized seating required by FMVSS 222 for school buses are lost, i.e., the seat back does not controllably collapse to absorb energy when an occupant strikes the seat back. Because school buses are often used to transport children, it is foreseeable that some children will buckle their seat belts while some other children will forget or refuse to buckle their seat belts.
Accordingly, it would be advantageous to develop a seat assembly that has a seat bottom that can flip up when not in use and a seat back that absorbs energy when occupants collide with the seat back during front-end and rear-end vehicle collisions while also providing adequate support for the seat belt assembly in the upright position such that the seat belt assembly properly functions when the occupant is buckled into the seat belt.